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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /drivers/hwspinlock/omap_hwspinlock.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'drivers/hwspinlock/omap_hwspinlock.c')
-rw-r--r--drivers/hwspinlock/omap_hwspinlock.c190
1 files changed, 190 insertions, 0 deletions
diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c
new file mode 100644
index 00000000..887d34ef
--- /dev/null
+++ b/drivers/hwspinlock/omap_hwspinlock.c
@@ -0,0 +1,190 @@
+/*
+ * OMAP hardware spinlock driver
+ *
+ * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * Contact: Simon Que <sque@ti.com>
+ * Hari Kanigeri <h-kanigeri2@ti.com>
+ * Ohad Ben-Cohen <ohad@wizery.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/bitops.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/hwspinlock.h>
+#include <linux/platform_device.h>
+
+#include "hwspinlock_internal.h"
+
+/* Spinlock register offsets */
+#define SYSSTATUS_OFFSET 0x0014
+#define LOCK_BASE_OFFSET 0x0800
+
+#define SPINLOCK_NUMLOCKS_BIT_OFFSET (24)
+
+/* Possible values of SPINLOCK_LOCK_REG */
+#define SPINLOCK_NOTTAKEN (0) /* free */
+#define SPINLOCK_TAKEN (1) /* locked */
+
+static int omap_hwspinlock_trylock(struct hwspinlock *lock)
+{
+ void __iomem *lock_addr = lock->priv;
+
+ /* attempt to acquire the lock by reading its value */
+ return (SPINLOCK_NOTTAKEN == readl(lock_addr));
+}
+
+static void omap_hwspinlock_unlock(struct hwspinlock *lock)
+{
+ void __iomem *lock_addr = lock->priv;
+
+ /* release the lock by writing 0 to it */
+ writel(SPINLOCK_NOTTAKEN, lock_addr);
+}
+
+/*
+ * relax the OMAP interconnect while spinning on it.
+ *
+ * The specs recommended that the retry delay time will be
+ * just over half of the time that a requester would be
+ * expected to hold the lock.
+ *
+ * The number below is taken from an hardware specs example,
+ * obviously it is somewhat arbitrary.
+ */
+static void omap_hwspinlock_relax(struct hwspinlock *lock)
+{
+ ndelay(50);
+}
+
+static const struct hwspinlock_ops omap_hwspinlock_ops = {
+ .trylock = omap_hwspinlock_trylock,
+ .unlock = omap_hwspinlock_unlock,
+ .relax = omap_hwspinlock_relax,
+};
+
+static int __devinit omap_hwspinlock_probe(struct platform_device *pdev)
+{
+ struct hwspinlock_pdata *pdata = pdev->dev.platform_data;
+ struct hwspinlock_device *bank;
+ struct hwspinlock *hwlock;
+ struct resource *res;
+ void __iomem *io_base;
+ int num_locks, i, ret;
+
+ if (!pdata)
+ return -ENODEV;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENODEV;
+
+ io_base = ioremap(res->start, resource_size(res));
+ if (!io_base)
+ return -ENOMEM;
+
+ /* Determine number of locks */
+ i = readl(io_base + SYSSTATUS_OFFSET);
+ i >>= SPINLOCK_NUMLOCKS_BIT_OFFSET;
+
+ /* one of the four lsb's must be set, and nothing else */
+ if (hweight_long(i & 0xf) != 1 || i > 8) {
+ ret = -EINVAL;
+ goto iounmap_base;
+ }
+
+ num_locks = i * 32; /* actual number of locks in this device */
+
+ bank = kzalloc(sizeof(*bank) + num_locks * sizeof(*hwlock), GFP_KERNEL);
+ if (!bank) {
+ ret = -ENOMEM;
+ goto iounmap_base;
+ }
+
+ platform_set_drvdata(pdev, bank);
+
+ for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++)
+ hwlock->priv = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i;
+
+ /*
+ * runtime PM will make sure the clock of this module is
+ * enabled iff at least one lock is requested
+ */
+ pm_runtime_enable(&pdev->dev);
+
+ ret = hwspin_lock_register(bank, &pdev->dev, &omap_hwspinlock_ops,
+ pdata->base_id, num_locks);
+ if (ret)
+ goto reg_fail;
+
+ return 0;
+
+reg_fail:
+ pm_runtime_disable(&pdev->dev);
+ kfree(bank);
+iounmap_base:
+ iounmap(io_base);
+ return ret;
+}
+
+static int __devexit omap_hwspinlock_remove(struct platform_device *pdev)
+{
+ struct hwspinlock_device *bank = platform_get_drvdata(pdev);
+ void __iomem *io_base = bank->lock[0].priv - LOCK_BASE_OFFSET;
+ int ret;
+
+ ret = hwspin_lock_unregister(bank);
+ if (ret) {
+ dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret);
+ return ret;
+ }
+
+ pm_runtime_disable(&pdev->dev);
+ iounmap(io_base);
+ kfree(bank);
+
+ return 0;
+}
+
+static struct platform_driver omap_hwspinlock_driver = {
+ .probe = omap_hwspinlock_probe,
+ .remove = __devexit_p(omap_hwspinlock_remove),
+ .driver = {
+ .name = "omap_hwspinlock",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init omap_hwspinlock_init(void)
+{
+ return platform_driver_register(&omap_hwspinlock_driver);
+}
+/* board init code might need to reserve hwspinlocks for predefined purposes */
+postcore_initcall(omap_hwspinlock_init);
+
+static void __exit omap_hwspinlock_exit(void)
+{
+ platform_driver_unregister(&omap_hwspinlock_driver);
+}
+module_exit(omap_hwspinlock_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware spinlock driver for OMAP");
+MODULE_AUTHOR("Simon Que <sque@ti.com>");
+MODULE_AUTHOR("Hari Kanigeri <h-kanigeri2@ti.com>");
+MODULE_AUTHOR("Ohad Ben-Cohen <ohad@wizery.com>");